<script setup lang="ts">
import { computed, ref, watch } from 'vue'

interface Fruit {
  id: number
  icon: string
  isChecked: boolean
  num: number
  price: number
}

const defaultArr = ref<Fruit[]>([
  {
    id: 1,
    icon: 'https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/ll.png',
    isChecked: false,
    num: 2,
    price: 6,
  },
  {
    id: 2,
    icon: 'https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/smt.png',
    isChecked: false,
    num: 7,
    price: 20,
  },
  {
    id: 3,
    icon: 'https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/tg.png',
    isChecked: false,
    num: 3,
    price: 40,
  },
  {
    id: 4,
    icon: 'https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/xg.png',
    isChecked: false,
    num: 10,
    price: 3,
  },
  {
    id: 5,
    icon: 'https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/yl.png',
    isChecked: false,
    num: 20,
    price: 34,
  },
])

// 水果列表
const fruitList =
  localStorage.getItem('list') !== null
    ? ref(JSON.parse(localStorage.getItem('list') as string) as Fruit[])
    : defaultArr

// ...

// 侦听水果列表的变化
watch(
  () => fruitList,
  (newValue) => {
    // 需要将变化后的 newValue 存入本地 （转JSON）
    localStorage.setItem('list', JSON.stringify(newValue.value))
  },
  {
    deep: true,
  }
)

// 删除水果
const del = (id: number) => {
  fruitList.value = fruitList.value.filter((item) => item.id !== id)
}

// 添加水果
const add = (id: number) => {
  // 1. 根据 id 找到数组中的对应项 → find
  const fruit = fruitList.value.find((item) => item.id === id)
  // 2. 操作 num 数量
  fruit && fruit.num++
}

// 删除水果
const sub = (id: number) => {
  // 1. 根据 id 找到数组中的对应项 → find
  const fruit = fruitList.value.find((item) => item.id === id)
  // 2. 操作 num 数量
  fruit && fruit.num--
}

// 全选和反选
const isAll = computed({
  get() {
    return fruitList.value.every((item) => item.isChecked)
  },
  set(value) {
    // 基于拿到的布尔值，要让所有的小选框 同步状态
    fruitList.value.forEach((item) => (item.isChecked = value))
  },
})
// 统计选中的总数 reduce
const totalCount = computed(() => {
  return fruitList.value.reduce((sum, item) => {
    if (item.isChecked) {
      // 选中 → 需要累加
      return sum + item.num
    } else {
      // 没选中 → 不需要累加
      return sum
    }
  }, 0)
})

// 总计选中的总价 num * price
const totalPrice = computed(() => {
  return fruitList.value.reduce((sum, item) => {
    if (item.isChecked) {
      return sum + item.num * item.price
    } else {
      return sum
    }
  }, 0)
})
</script>

<template>
  <div class="app-container" id="app">
    <!-- 顶部banner -->
    <div class="banner-box">
      <img src="https://hongm-1312445828.cos.ap-nanjing.myqcloud.com/sg_top.png" alt="" />
    </div>
    <!-- 面包屑 -->
    <div class="breadcrumb">
      <span>🏠</span>
      /
      <span>购物车</span>
    </div>
    <!-- 购物车主体 -->
    <div class="main" v-if="fruitList.length > 0">
      <div class="table">
        <!-- 头部 -->
        <div class="thead">
          <div class="tr">
            <div class="th">选中</div>
            <div class="th th-pic">图片</div>
            <div class="th">单价</div>
            <div class="th num-th">个数</div>
            <div class="th">小计</div>
            <div class="th">操作</div>
          </div>
        </div>
        <!-- 身体 -->
        <div class="tbody">
          <div v-for="item in fruitList" :key="item.id" class="tr">
            <div class="td"><input type="checkbox" v-model="item.isChecked" /></div>
            <div class="td"><img :src="item.icon" alt="" /></div>
            <div class="td">{{ item.price }}</div>
            <div class="td">
              <div class="my-input-number">
                <button @click="sub(item.id)" :disabled="item.num <= 1" class="decrease">-</button>
                <span class="my-input__inner">{{ item.num }}</span>
                <button @click="add(item.id)" class="increase">+</button>
              </div>
            </div>
            <div class="td">{{ item.num * item.price }}</div>
            <div class="td"><button @click="del(item.id)">删除</button></div>
          </div>
        </div>
      </div>
      <!-- 底部 -->
      <div class="bottom">
        <!-- 全选 -->
        <label class="check-all">
          <input v-model="isAll" type="checkbox" />
          全选
        </label>
        <div class="right-box">
          <!-- 所有商品总价 -->
          <span class="price-box"
            >总价&nbsp;&nbsp;:&nbsp;&nbsp;¥&nbsp;<span class="price">{{ totalPrice }}</span></span
          >
          <!-- 结算按钮 -->
          <button class="pay">结算( {{ totalCount }} )</button>
        </div>
      </div>
    </div>
    <!-- 空车 -->
    <div class="empty" v-else>🛒空空如也</div>
  </div>
</template>

<style scoped>
@import './style/inputnumber.css';
@import './style/index.css';
</style>